n = int(input())
c = input()
d = c.count('R')
e = c[:d].count('R')
print(d-e) n = int(input()) n int(input()) int input() input c = input() c input() input d = c.count('R') d c.count('R') c.count c count 'R' e = c[:d].count('R') e c[:d].count('R') [:d].count [:d] c :d d count 'R' print(d-e) print d-e d e n = int(input()) int(input()) n c = input() input() c d = c.count('R') c.count('R') d e = c[:d].count('R') c[:d].count('R') e
n = int(input())
c = input()
d = c.count('R')
e = c[:d].count('R')
print(d-e)